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VAST: Video & Audio Advertising

What is VAST?

VAST - the Video Ad Serving Template - is the standard IAB introduced to make video and audio ad serving work across players from different vendors. It uses an XML schema to carry an ad's metadata from the ad server to the video or audio player.

Adhese fully supports VAST: we are compliant with VAST 2.0, 3.0, and 4.0 and can help you adopt its guidelines.

VAST offers a set of features intended to make online video advertising easy.

  • Platform—and device-agnostic: Nothing about the protocol of VAST is specific to the functioning of a certain device or platform. This allows Adhese to serve ads across several video players in different situations, such as websites, mobile websites and applications, Internet-connected TVs, or set-top box environments.
  • Support for different ad types: VAST supports different video ad formats. Next to the well-known linear and non-linear video ad formats, VAST enables the delivery of companion ads, skippable linear ads, and ad pods.
  • **Tracking:**To provide details about the delivered ads, VAST enables the simultaneous tracking of several user events related to the video ad. That is to say, VAST can tell you, for example, whether a video ad was completely viewed or if the user has muted the sound. VAST can also notify you if a user skipped a linear ad by explicitly closing it before completion, or if the user clicked a non-linear ad away.
  • Detailed error reporting: When a video player cannot display an ad, VAST enables the player to provide specific feedback to the ad server about why the ad can not be served.

More information on VAST can be found on the IAB's website. Detailed documentation on the latest version can be found in this PDF. 

How does a VAST setup work?

The player requests an ad from the ad server using a simple URL. This is usually done using the AD endpoint. Adhese then answers with a VAST XML document the player knows how to read. That document is assembled from two building blocks: advar templates, which supply the static VAST markup, and creatives, which are used to provide the media itself together with other META data.

The media can be provided in three ways:

  1. By uploading the material in Adhese
  2. By providing a link to material hosted on a different domain
  3. By providing a link to an external VAST tag. Adhese will in that case redirect to the external tag while maintaining the ability to track events

Because a template holds static VAST markup, each type or version of media you want to serve, will require its own template.

Simplified response example

<VAST version="4.0">
  <Ad id="19787">
    <InLine>
      <AdSystem>Adhese</AdSystem>
      <AdTitle>Your creative</AdTitle>
      <Impression><![CDATA[ …/impression ]]></Impression>
      <Creatives>
        <Creative>
          <Linear>
            <Duration>00:00:15</Duration>     
            <TrackingEvents>              
              <Tracking event="start"> … </Tracking>
              <Tracking event="firstQuartile"> … </Tracking>
              <Tracking event="complete"> … </Tracking>
            </TrackingEvents>
            <VideoClicks>
              <ClickThrough><![CDATA[ …/click ]]></ClickThrough>
            </VideoClicks>
            <MediaFiles>                  
              <MediaFile type="video/mp4" width="640" height="360">
                <![CDATA[ …/creative.mp4 ]]>
              </MediaFile>
            </MediaFiles>
          </Linear>
        </Creative>
      </Creatives>
    </InLine>
  </Ad>
</VAST>

Video ad types

Video | Linear Since VAST 1.0

In-stream video ads that interrupt the main video content. They include Pre-rolls (playing before the video), Mid-rolls (playing during), and Post-rolls (playing after). These usually include skippable or non-skippable formats (introduced in VAST 3.0). 

Video | Companion ads Since VAST 2.0

A companion ad is a image ad shown alongside a linear video ad, usually displayed on top of the player or on its side. It is displayed at the same time as the video ad and can continue to be displayed after the video has finished playing. 

Video | Outstream Since VAST 2.0

The video ad appears in non-video environments, typically embedded in text-based content such as articles or news feeds. An outstream video could for example be shown in typical display placements such as a 'medium rectangle'. 

Video | Non-linear Since VAST 2.0

The ad runs alongside the content, typically as an overlay, without interrupting playback.

Video | Ad pods Since VAST 3.0

A group of ads that play in sequence during a commercial break during long-form video content. Specifically, using IAB VAST, an ad pod is a group of sequential ads that can be served in one VAST tag.

Video | SIMID Since VAST 4.0

VAST can carry interactive ads, not just straight playback. The current standard for that is SIMID - Secure Interactive Media Interface Definition - IAB's successor to the now-deprecated VPAID.

The interactive layer is an HTML creative that the player loads into a sandboxed iframe and talks to over the postMessage API, so it can drive clickable overlays, menus or dynamic calls to action without ever touching the player itself.

An Adhese templates can provide the option to add a link to an externally hosted HTML layer. Creating and hosting the interactive layer in Adhese is not possible. 

More info on the SIMID standard: https://iabtechlab.com/wp-content/uploads/2022/09/SIMID-1.2.pdf

Audio ad types

Audio | Linear Since VAST 4.1

Audio ads that play in a vendor's digital audio player. They are handled similarly to video creatives, except they only have audio and no video component.

Native audio arrived in VAST 4.1, when the separate audio spec (DAAST) was folded back into VAST - before that, audio was served through DAAST as its own template.

Audio | Companion ads Since VAST 4.1

An audio companion ad pairs a linear audio ad with a synchronized image on a screen. This setup allows advertisers to deliver a voice-driven message while providing a clickable asset for direct response. Ideal for music or podcast applications.

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